This paper summarizes the fourth Evaluating Collaborative Enterprises (ECE) workshop, held as part of the 12^th IEEE International Workshops on Enabling Technologies: Infrastructure for Collaboration conference (WETICE 2003), at the Johann Kepler University, Linz, Austria. This paper introduces the seven papers presented and summarizes the presentations and ensuing discussions of the participants of the ECE workshop. In addition to the discussions following the papers, a panel session was held. This report sets the scene by summarizing the development of the Evaluation workshops over the past four years, and assesses the current state of practice in Evaluation of Collaborative Enterprises. Paper topics in this workshop addressed evaluation at different stages of the development process and evaluation methodologies at groupware evaluation. Discussion addressed effectiveness measurement, selection of appropriate instruments and different perspectives from group members.